... 'the search' is for something either easier to tie or which is a no-slipper that can be untied.

Or for something that breaks above 50 % ? How do we know that the 50% is the maximum we can achieve ? Easy answer. We do not.

Actually empirically what we know is #1 that no knot has tested statistically above 50%, #2 That the 5 brummel, which is a tuck type splice, is 80% of line strength, and the full bury splices are 100%. And theoretically what we know is given the specific dyneema bend radius strength curve, we can quite strongly argue that no knot with a bend radius of 1:1 in it will ever be stronger than 50%, and I would suggest it is impossible to design a knot that does not have a 1:1 bend radius in it.

One thing we should NOT take for granted nowadays, is what will be the practical application of whatever in "a sailing boat" - sailing boats are vehicles, they do not remain the same ! Unless somebody can claim that the mechanism used to adjust the inclination of the fully submerged foils in the America s Cup sailing boats last year were foreseen by anybody ! Noope, nobody can predict which the practical applications of a knot will be - and one GREAT example of this is the use of the reef bend on the tube of a bicycle ! (1). We do not want to learn about knots, because we have a fixed idea about a fixed mechanical problem of a fixed mechanism which we want to solve with a knot... We want to learn about knots because we like to do it - and because knowledge is a the most practically useful thing the Universe has created !

I did not say we will not find other applications for loops. I said there were not other applications for bends, because an end for end splice is the better solution whenever it is possible. That is just a plain fact.

I am skeptical that we will find a better practical solution for this application, but if we do, I expect it will be more along the lines of...

Expectations should be based on adequate experience, and nobody has adequate experience with bends tied on such material. Of course, if you had discovered the wheel, you could be sceptical about better practical solutions, indeed ! However, there are HUNDREDS of back-to-back-hitches /nooses that have not been tested by anybody, for example. And, of course, HUNDREDS of re-tucked simple bends as well. I admire the boldness of the scepticism of somebody who believes that something will never be improved - but I trust more somebody who does not believe in beliefs...

hmmm . . . first, you have no idea how much experience I have testing bends in this material. I would suggest it is 'adequate' to express some skepticism. And second, I said that an important criteria for success was a low profile result. That makes my following comment about looking at long fishing knots over rounder knots almost by definition.

Among other things. Alternating loading should also be considered. The force by which the bend was pre-tensioned in the first place, during its dressing, would also play a role, IMHO. So, one should always pre-tight the bends he is going to test with a certain, always the same, load. I think that nobody yet has been convinced that the bends tied on thin and thick lines will behave the same way - although I, for one, hope that this is the case, indeed, and that the mere scale of the ropes we test will be irrelevant, provided all other things remain, proportionally, the same. JP has reported some results, but he has not repeated them on thicker lines.

Look in theory you should control for "everything", but in practice you need to focus on what is really driving variation. I don't know how much experience you have doing pull tests, but I now know what makes for important statistical variation and what does not. In this slipping case the important factor is pull speed.

I recently did some scaling tests. I can summarize them if you are interested.

empirically what we know is #1 that no knot has tested statistically above 50%...

In your mind, as you rightly said ! If I had seen two, or a dozen white swans all and all in my life, empirically what I "know" is that no swan is black - and I might even claim, sceptically, as you do, that there will never be any black swan anywhere in the Universe - because, as Leibniz said, this World is the best, so it is the only possible !

So, when you will test the 60-120 known simple bends I have suggested to you, and the 60-120 centrally re-tucked versions of them, then you will "know" something... You have tested what you said is "THE Sheet bend", and "THE fig.9 knot", without even realizing that there are TWO Sheet bends, and THREE fig.9 knots, for KnotGod s sake... And I do not even count how many different dressings / loadings combinations "THE fig.8 knot" can have... So, I guess that, although you have done a wonderful job, you have still some distance to cover before you start claiming that "we know".

I would suggest it is impossible to design a knot that does not have a 1:1 bend radius in it.

? ? ? You would nt bet on this, I suppose... Because I know dozens of such bends ! Does the retraced overhand knot = Water bend, for example, have a 1:1 bend radius in it ? Or, for that matter, most the fig.8 knots you had mentioned ? I guess I have not understood what you say/mean here.

the only real practical application (on a sailing boat anyway) for bends in bare dyneema is to make fixed loops which are too short for an end to end splice, and un-tieing is really not all that critical feature for those... So, practically speaking I am happy with the solution we have already found. I am skeptical that we will find a better practical solution for this application, but if we do, I expect it will be more along the lines of ...

Your reasoning is not very convincing here, I am afraid - and the retreat to the splices sounds almost as a desperate defence. We have to test all the closed, by end-to-end knots or hitch to hitch knots, loops we know, before we can "know". If you abandon knots, you may even abandon splices and search for a nice cheap glue, or a mechanical fastener. Practically speaking regarding you, you do deserve to be happy. However, practically speaking regarding our knowledge about knots, we are veeery unhappy / sorry we know next to nothing !

I don't know how much experience you have doing pull tests, but I now know what makes for important statistical variation and what does not. In this slipping case the important factor is pull speed.

1. NONE 2. So, the other factors I had mentioned do not contribute in an "important" statistical variation? In what sense ? How you know before hand what is "important" in a distribution, if you do not know what form this distribution should have ? If you say they will not vary the results more than, say, 1%, I will agree - provided that the differences of the pull speed factor would be, say, ten or fifteen times more ( 10% - 15%)- but is this the case ?

hmmm . . . first, you have no idea how much experience I have testing bends in this material. I would suggest it is 'adequate' to express some skepticism. And second, I said that an important criteria for success was a low profile result. That makes my following comment about looking at long fishing knots over rounder knots almost by definition.

I apologize for anything that have said and it sounded like I think it sounded to you. I am sure that you have dozens, if not hundreds of times more experience than me - but this is still not adequate, I am afraid ! I read your site, and I see the number and kind of bends you refer there - and I would suggest this reading is "adequate" to express scepticism about your knowledge of bends - which, I repeat, may well be much more extended than mine s. However, I happen to know that there is no One Sheet bend, One fig.8 and One fig,9 knot, and to know the 120 known bends - while you do not... So, we(plural) have many knowledge to exchange, before we can claim that we "know". First, you mentioned the "facts", now you mention the "definitions" ! My feet have not started trembling, though... Have you measured the maximum width of the cross sections of even the very few bends you have tested ? If yes, where are the NUMBERS ( in cm, of course ..., not in Hers Majesty s inches ). And of HOW MANY BENDS have you measured the maximum widths of the cross sections ? How have you strengthen your belief that the minute sample of bends you have tested is "adequate" to jump into such broad conclusions ? Of course, a long-long-long fishing knot, tied by spin-spin-spin entangling, would be sleek, strong and will not slip. So you propose to tie the dyneema bends with fishing knots, and fishing knots only ? If so, I have to pull out my fishing knots memories, which I had buried dozens of years ago. Now, I eat fish in the restaurants - I even would not allow cooking of fishes in my apartment, because I can not stand the smell of the fresh fish more than 1 minute.

Oh ! I am sure Dan Lehman would had preferred a lower maximum load, if it would be accompanied by an acceptable, at least, looks - but, with this mass body ratio, what would he expect ? I suggest bicycling, mush uphill bicycling ! The "bowled over and retucked" whatever should better be stored in the not-bowled basket under our desk, we call waste basket...

P.S. I see that this fat ugly tangly has been tied in two parts of the same loop ? As a friend of mine once pointed out to me, there can be some kind of invisible interference we can not predict or explain between those two knots, so the pull on the one is absorbed earlier or later within the nub of the other, vibrations and minute variations of tension could spread from the one to the other, etc. I believe that it is better to test loops with one only bend on them - and with their two tips wrapped around bearings, not pins that can not follow micro-rotations of the loop while it is tensioned, so they "protect" the bend(s), as it has been reported.

But honestly, the only real practical application (on a sailing boat anyway)for bends in bare dyneema is to make fixed loops which are too short for anend-to-end splice, and un-tieing is really not all that critical feature for those.More important is low profile compactness

Let me ask : would this application be ableto use a "loop" that was built by knottingboth sides of a mid-section of line --rather thanjust the two tails? In that "the chain is nostronger than its weakest link," I've wonderedmaking both *sides* of such a "loop" participatein the knotting, which might enhance strengthand security aspects; but which would meanthat the end points of the loop were fixed(think "dog bone" for structure; each halfbeing a sort of loop). As an example, theopposite-to-ends side could form a loop(overloaded term, "loop", argh) /circle, 'a labowline and then each tail could respectivelybe tucked through this in a bowlinesque way.(Now, I think that this particular knot is NOTso secure; but it's just an example ... .)

If such a structure (which might place the knotcloser to one end, to provide large/small loops)is feasible, this might be a direction worthpursuing.

Quote

Here's a pic of back to back estar's,

Thanks. And if you can zoom in for a morerevealing photo (esp. of a highly loaded knot,to see what's going on in compression andnip), that'd be a bonus.

P.S. I see that this fat ugly tangly has been tied in two parts of the same loop ?As a friend of mine once pointed out to me, there can besome kind of invisible interference we can not predict or explain[but can conjecture, like the existence of unicorns]between those two knots, so the pull on the one is absorbed earlier or laterwithin the nub of the other, vibrations and minute variations of tensioncould spread from the one to the other, etc.[and butterfly-wing vibrations in South America could do magic!] I believe that it is better to test loops ...[vigorously vicariously]

I can not recognize what is on a man s or Dan Leh-man s mind... However, I can tell that its contour reveals a body mass index which requires cycling, much uphill cycling, in order to lose some redundant weight. I, too, have tied many bowl-like bends, but I dared to show only those which, although they are certainly not slim, and may be characterized portly, are NOT ugly. The old Strangle bend (1), or the recent "yet another bowl" (2), for example. I am sorry, but the "bowled over & re-tucked" whatever IS ugly, and it is not a matter of politically correctness to recognize and tell this. ( The "bowled over." ( = bowled over, period ), before it swallows its Tails, is OK ). I did not say this because of the particular application e-star and allene had in their minds - on board of a sailing ship, when the ship itself and the rope is moving, it is better if we tie slim knots, with a small cross section, for many reasons. I said it because we have to draw some lines, place some limits on the volume of the practical knots we are ready to tie, just as we place limits in their complexity regarding their tying, for example. I think that the "bowled & re-tucked" whatever crossed the limits I have in my mind ! And I was not polite or politically correct enough in the way I said what was in my mind, because I am still behaving according to the feeling this "riduculous"(sic) characterization Dan Lehman had used (4) for the most beautiful Oyster bend / Threefold ( M. B5)(3) I had proposed to test, because of its tightness. The "fat ugly tangly"(sic) was just another knee-jerk reaction to the reminiscence of this "riducurlous"... Mea Culpa. Now, here comes the interesting question. Let us suppose that, in order tie a end-to-end knot between two Dyneema lines, we discover that we really need something of volume or tying complexity beyond the limits we have in our mind. What will we do ? As far as it concerns me, I have answered this question in another occasion - in the case of midline-to-midline bends. If we will be forced to tie a very bulky knot, we simply will NOT tie ANY knot, we will solve our rope-joining problem with some other means. However, the re-tucked alternative Carrick mat of allene is not a very bulky knot, and I am sure that there are dozens of acceptably bulky knots that can do the job, without having to go fishing. To me, a practical knot is something that can, in theory, be used in practice. I do not believe that people will ever tie very bulky or very difficult to remember how to tie and to actually tie practical knots. In our mind, a practical knot is not just any entangled segments of ropes. It is a "small" lump along the line - if this lump is bumped, the definition of the practical knot itself is bumped, and, at the end, we will start to consider, as practical knots, the tangled spaghettis in our bows...

there can be some kind of invisible interference we can not predict or explain between those two knots,[but can conjecture, like the existence of unicorns]

...vibrations and minute variations of tension could spread from the one to the other, etc.[and butterfly-wing vibrations in South America could do magic!]

]

I believe that no scientist worth its salt would ever think to test two connected things, the one next to the other, when he can well test each one separately. I am not saying that the influence would be huge - I am just saying that there can be a influence, and that, at least before we do some tests, it is better not to underestimate its magnitude beforehand. I imagine that those two knots can, somehow, work ij tandem, and each one can absorb some vibrations or sudden increases of the tensile forces that would had made the other break - because we can not be sure that both knots were dressed or pre-tensioned in the exact same way. Of course the bump that made Dan Lehman mind vibrate was not this absolutely reasonable comment on the cautious way we have to perform our experiments - it was my characterization of his "bowled over and re-tucked" whatever, that made his square-wheeled bicycle or his unicorn to jump up, and drag his mind with it. Did it step on any other soOo elegant "superbowled-over & re-re-tucked" knot of his ? Who can tell ? Who can read what s on a man s mind ?

Why is this "Bowled-over & re-tucked" whatever soOo bulky ? The answer is simple : Because it is NOT a "re-tucked" simple bend, it is a re-re-tucked simple bend ! Re-, Re-, Two times ! ( After some more, we would had started to listen the music of it in our ears... ). As I had shown in (1), and one can see in the attached picture, this bulky tangle is the result of two reiterative, adjacent tuckings, on the simple Carrick-like mat of two most simply interlinked bights shown below. For comparison, the "Illusion" (M. B25)( = lR-uL, i.e. re-tucked through the lR = left Right opening of this mat, for the one tail, and through the uL = upper Left opening of this mat, for the other tail ), is re-tucked once. ( See the third attached picture ). It is like you eat two full bowls of spaghetti each time, and you still wish to remain slim. This is the kind of magic which may be current in South or Central America, but is not allowed in the KnotLand. If you re-tuck too much, you become over-weighted. We should be happy that there are some limits in the complexity of the possible practical knots, otherwise we wouldn't bother to tie them - as nobody bothers to tie the 177.147 different distinct tie knots (1).

Another thing one may "add" to Ashley s #1452 bend ( other than 180 degrees additional turns of the segments around the central opening, as in the bend shown in this thread ), is shape "8" collars around the Standing Ends. We have seen something like this some time ago : see the attached pictures presented at (1), and also the knots presented by Luca at (2).

...it is only the first (double collar) version I'd use. You might try an in-between version, where the main loop goes not 180degor your 540 but 360 degrees, to collar the opposite line.

At the posts referred below (1), I, too, has tied some double collar variations of the Hunter s bend in the past, which may look "similar" ( but they are not : The Zeppelin and the Hunter s bends are topologically and structurally very different knots, so not "similar" at all ! ). In the back of my mind, the purpose of the re-tucking was to force the first curves of the Standing Parts become rounder and wider - so it was related to the strength, not to the security of the knot. I would nt believe that such a complication would be dictated by the so low friction coefficient of those extra-ordinary materials... The main thing which is "doubled" ( well, almost doubled - it is bowled over 1.5 times ) in this enhanced Zeppelin bend, is the nipping loop, not the collar. The same "duplication" can be attempted in all the numerous variations of the Hunter s and the falsely tied Hunter s bends. However, those four interlocked double nipping loops, although they do not affect too much the easiness of the parent Zeppelin bend s untiability ( they do, but in an acceptable degree, I think ), they make the already too tight, and prone to jam, Hunter s bend, even more problematic... and the same should be said for the re-tucked True Lover s bend (2), and the Strangle bend (3). We should better think twice before we interlock double nipping loops (4).

This bend to me appears as a sort of "tressed" version of the double Zeppelin (B2) shown by xarax in this post: http://igkt.net/sm/index.php?topic=1980.msg13796#msg13796The bend is absolutely no tested,so I have no idea whether it may add something to the version linked above. Below I propose two possible dressing: the first is the more spontaneous result by following the method( maybe tricky,but not so tricky!) proposed in the diagrams in the fourth pic;I like the way in which the working ends are "nipped",but the second,more..ehm.. "slim",dressing,however, could be more stable and maybe strong, but they are only my impressions (or imaginations! ).In any case, the first dressing seems to have a greater benefit in stability in the case in which also the collars are doubled (third pic below:one pound of Zeppelin all for free! ) as shown at reply #8: http://igkt.net/sm/index.php?topic=4777.msg31022#msg31022 .

Going further all the way, the "kinky" dressing starts to look like the knot shown in the attached picture. The optimum "right" 90 degree angle between the axis / pin of the hinge, and the first curves / knuckles of the hinge, has disappeared, and instead we see a 60 degrees angle - so, at the point of contact between the first curves and the Tail ends, we will have friction forces, not only sheer forces... The bend became less Zeppelin-like ! (1)

In knots, rope segments should either bite each other / meet at right angles, or caress each other / be parallel. There is no point of one segment "jumping" over the other ( unless it is a riding turn, and squeezes it on the hard surface of a pole, as it happens in the "snug" hitches ). Such a "kink" neither generates enough friction, because the segments can easily slide on its other s surface ( if we want maximum obstruction of movement, we better have segments squeezed onto each other, while the meet at right angles ), nor it enables an unobstructed flow of the lines inside the nub, which will re-distribute the tensile forces on a greater area. Another disadvantage of this dressing, is that the knot becomes less easy to inspect - which is a great plus of all symmetric knots, in general, and of the Zeppelin bend, in particular.

If you have written about the bend in your black and white photo you are right 100%, but taking a look at the bend shown in the pathetic imitation of your picture attached below... probably you would continue to be right!But maybe "a little less" ...The setting shown here corresponds to the result that I get spontaneously using the method described above (no, it is not true, I confess: I gave a pull on the tails!):the kinks are less kinky,the tail ends exit(almost)perpendicular to the standing ends(but I must say that I do not know what can happen under heavy loads),and some curvatures of the collar are less sharp.But the fact remains that the flaws you explained,mentioned just in an embryonal way in my first post,are present, although to a(much?)lesser extent.So probably, if one wants to apply to the "normal" Zeppelin bend only a doubling of type B2, the "standard" B2 is perhaps the best solution, because more stable (but the "normal" Zeppelin it is even more), more self-dressing (but even here I give a little pull on the tails ...),and surely more easy to inspect.But the problems of stability of the "tressed" version seem to disappear after the moment in which one applies also the doubling of the collars(and even the kinks seem to be even less evident!);therefore the basic question might be:using Dyneema rope,which may be the comparative results of tests made in the Estar way,between the double collared "standard" version B2 and the double collared "tressed" version B2?

Pay attention to my first sentence : Going further all the way... In your picture, you show a knot where you had not - a knot where you had remained in the same in-between, intermediate stage, which eventually, at the very end of the transformation, will lead to the knot I show. The "jump" of the one segment over the other, which will produce the "kink", has not been finished yet in your knot : when it will be finished, when the riding turn will be transported all the way, to the other side of the turn underneath it, you will get the knot I show. Imagine the central pair of the Tail Ends as an axle. The three turns "revolve" around this axle, so they will be adjacent and in contact to this axle more than to themselves. Under heavy loading, I do not believe that the "kink" would remain in the form you show. It seems to me that the form I show is the final stage, and the form you show is only an intermediate, not very balanced one. If you tie the knot in Spectra/Dyneema, perhaps we can settle this. Perhaps we will see that both forms, the form you show and the form I show, are equally stable, so we will both be right 100% !

Aha ! In a heavy loaded bend, the effects of this pull will be "swallowed" by the effects of the pull of the Standing Ends, which will force all the turns to turn around the central, less loaded and more immobilized part, the pair of Tail Ends. So I think that we will get three turns which will be as much embracing their common central axis as they can, i.e. we will get the form I show.

"the tails ends still exit perpendicularly to the standing ends"... is the correct expression ! Wait and see what will happen next ! The pulling of the turns will force them to settle, the one next to the other, on the surface of the axle, as I show.

Unfortunately these days I do not have access to my "laboratory", but I found a piece of "rope" that served as a handle of a cardboard shopping bag : the material is very elastic and extremely compressible, stuff that proved to be very suitable for distort a knot (if it has to distort) with the sheer force of the arms.I think that the result of the "test" visible in the first pic below is "OVER all the way"!And give you rightness more or less all along the line ...However, the "test" on the re-collared version(second pic) gave good satisfaction on my assumptions about his acquired stability.So,given his stability(yes,still not seriously tested),it is stronger(I don't think) of the bend at reply #8?Or Is less prone to slip?(maybe I guess,unless it does not break before...) To posterity the arduous judgement!